Turbine control system



March 14, 1933. 1 1 RlNG 1,901,776

TURBINE CONTROL SYSTEM I Filed April 7, 1952 Y "arm 34,

floating lever27 is provided with a roller 30 which is adapted to be pressed into engagement with cam 31 by means of sprin 50.

vCain 81 isattached to shaft ,32 whic is carried by suitable bearings. Shaft 32 is rotatableulliy servo-motor'33 through crank 35, and piston rod 36. Servo-motor 33 is controlled in a usual manner by a pilot valve having a stem 3 7 which controls the admission of operatingA fluidunder pressure from inlet pipe 38. Valve stem 3 is pivotallyconnected to the left hand end of floating lever 39 which is actuated by a ilyball governor-41 suitably driven in accordance with the-speed of turbine 10. The'motion of piston rod 36 is' relayed to the right hand end of-floating lever .39 in a usual mannerthrough compensator device 42, link 43, bellcrank 44 and link 45. A cam 46 is also attached to shaft 32 and is thus adapted to move simultaneously with cam 31. A roller 47 is carried by one arm of bell crank 48 and is pressed into engagement with cam 46h spring 49. The other arm of bell crank 8 is suitably connected to valve stem of rotor blade tiltin servomotor 56 by means of rod 51, be crank 52, and link 53. Any suitable type of rotor blade tilting servo-motor may However, a servo-motor of the type wherein the amount of movement of a control valve directly determines the amount and rate of travel of the servomotor piston is herein shown in Fi.` 2. In general the servo-motor shown in iggo2 comprises a cylinder head 57 having a re adapted to receive valve stem 55, and a cylinder member- 58 provided with a base rtion 59 for connection to the erator e 60 in which guide bearing 61 for erator shaft 62 is located. Cylinder mem r 58 is rovided with a bore in which piston 63 is apted to slide. Piston 63 is provided with a sleeve portion 64 which is adapted to slide through another borevin cylinder 58. g Rotor bla e tilting rod 65 is rotatably connected -to piston 63 by means of a double thrust b ea 66. Servo-'motor 56 is also provided wi a pressure inlet pipe 67 which isadapted to conduct fluid under ressure through orifice 68, around thrust ring 66, thro h passage way 69, out valve member 70, t ro h `drain conduit 71 and out drain pipe 2.

Upon rai of.valve stem 55 the pressure of the uid above piston 63 dropsv by reason of the small orifice 68 thereby caus-` ldigthe operat' the piston 63 to rise under the influence Afluid within the annular between eeve 64 and cylinder 58. pward movement of iston 63 causes valve member 70 to restrict e passageway therethrough, thus permitting pressure to buildu in the space above piston 63'until equil rium is established. The effective area of the upper aide of piston 63 is greater the e ective area ofthe lower side thereof, .4

consequently it is possible to move piston 63 downward ward to restrict the opening in valve member 70.

The modified 'form :of um mechanism.

shown infFig. 3 comprises a shaft 32 upon which cams 31A and 46A are free to rotate. A lever 74 is xedl attached to shaft 32 and is adap to be connected to iston rod 36 of servo-motor 33 bymeans o link 35. The u per portionof lever 74is provided with a aring for carrying shaft 75 which is free to rotate therein. One end of shaft 75 has attached thereto a pinion 76 which meshes with ar sector 77 of cam 31A. The outer end o shaft 75 has attached thereto a pinion 78 which meshes with gear sector79 of cam-46A. It is to be noted that 77 is a sector of an internal 'ring gear, whereas, 79 is a sector of an external ring gear-, A

shaft 81 is xedly attached to ade iiding l Fihl,

e operation of the system is as follows:

ymoving valve stem 55 downrovided wit ardepending portionioo The various elements of the system shown in Fig. 1 are in Positions corresponding to substantially hal load operating conditions on the turbo-generator unit. Upon decrease -iii turbine speed due to an increase of load,

the flyballs of overnor 41 will move inwardly thereby lifting iioating lever 39 and valve stem 37 which causes fluid under. ressure to flow from inlet pipe 38 throug the left hand'inlet pi of servo-motor 33. Servo-motor 33 is t ereupon caused to rotate cams 31 and 46 in a counter-clockwise direction. Roller 30 in following the contour of cam 31 causes floating lever 27 to pivot on link 28 thereby lifting valve stem 26 which permits fluid under reure to flow from inet pipe 25 to the right hand side of servomotor 20. Servo-motor 20 is thereupon caused to move guide vanes 14 through linkage comprisin piston rod 21, crank arm 22, shaft 23, cra -arm 24, rod 16 and actuating ring 15 to admit more water to the turbine 10. The motion of guide vanes 14 is relayed through the above described linkage 'to bell crank 29 so las to cause link 28 to ios iis

crank 48 in e clockwise direction thereby causing valve stein 55 oi servo-motor 56 to move upwardly. Reierring more particulerly to Fi 2, u ward movement of valve stem 55 re uces t' e restriction of the opening in valve member l thereby decreasing 'the duid pressure on the upper surface oi piston 63y so that piston o3 is caused to move rotor blade tilting rod 65 upwardly. 'Upward movement oi rod 65 causes rotor blades 19 to increase their tilt, that is, to become more nearly parallel with the axis ci the rotor. The tilting i, movement oil servo-motor 56 is stopped when piston 63 moves uowardly to such e point that the opening in valve member 70 1s so restricted that the pressure on tlie upoer surface of piston 63 substantially eque s the pressure on the lower surface oi this piston.

it is to be noted that motion of piston rod to the right is relayed to the right hand end ot iloatin comprising linie' 45, bell cranlr i-i, linlr i3 and compensator i2 to thereby restore valve stem 37 to its neutral position. 'it is thus seen tliet the above described relay mechanisni is not connected directly to the guide vane adjusting rneclienism as has been the practice heretofore, l

Upon increase o' speed due to a decrease of load9 the ilybells oi governor il 'will move ontwardly thereby depressing i'loating lever 39 veive stem 37 which causes i'lnid under pressure to dow irom in- L pipe 38 through 'die ri lit band inlet servo-motor 38. erro-motor 33 Lerenpini caused to rotate cams 3l and iii a clockwise direction. Roller 30 in #ovvi ,c com 3l will cause valve stein 26 to .move downwardly thereby causing'servomotor 20 to move guide venes i4 in sncli n direction as to restrict tlie ilow ofi water to turbine l0. Rollerv ,-/li' in tlie following cam 6 causes valve stern 55 to move downwardly thereby causing servo-motor to move rotor blade tilting; rod 65 in suoli a direction tiret tbc rotor blades are iattened. it is thus seen that es tire speed ori the turbine changes in response to changes o'f load, the guide vanos and rotor blades will be simultaneousiy moved suoli directions as to restore the speed of seid turbine and 'to adinet ist' ` clockwise e lever 39 through linkageV hold this cem stationary. The counterclockwise movement oi shaft 'l5 will therefore cause inion 78 to rotate in a counter` irection on gear sector 79. The counter-clockwise rotation or" gear 78 as well as the trenslato movement of shaft 75 will be transmitte to pinion 76 which thereb causes cam 31a to rotate in a counter-cloc wise direction. Due to the fact that a translatory motion es well as rotation is imparted to' shaft 75,' the earn member 31a will, be caused to move substantially twice as far as would be the case ci cam 31a was xed to shaft 32 for a purpose to be bereinefter'described. Roller 30 in following cam 3io will cause valve stem 26 to move downwardly thereby causing servo-motor 20 to move guide venes 1lik so es to increase the dow o' water through turbine 10. Cam 31o in moving in a counter-clockwise direction causes cam 46a to be biased in a counter-clockwise direction by means ci centering springs 83, Si. @am 46a is therefore permitted to slowly rotate in a counter-clockwise direction at a speed determined by the adjustment oi dash-pot 88. llt is noted that tlie counter-clockwise rotation of cani 46a causes cloclrwise rotation ci pinion 78 which thereupon drives pinion 76 in a clockwise direction. The clockwise rotation of pinion 76 tlins moves cam 31e toward its initiel position in a clockwise direction es cani ed@ moving in a counter-clockwise direction. The coinbined movement of cam Bla and los will in time cerise the depending portion of 46a to move to a neutral position relative to centering springs 83 and Roller 47 in following cani' 46a raises valve icm 55 so tliet servo-motor 5-5increases elle tiit ot the rotor blades' 19.

inasmuch as the guide venes can made to operate in .a mucli slnnten tbnn tbe rotor blades, the above described cern mechanism permits the guide vanos to be opened an amount more than nally necessary upon increase oi load and permits tlie rotor blades to slowly essunie the position oi maximum efficiency. Since tlie movement of the rotor blades i9 to their more eiiicient position ail-ter a movement tbe guide venes lli nas tbe tendency to conse the turbine to operate at a, higher sneed dee to the inceresed eiciency, it is possible with 'this mechanism to reduce tbe guide vene opening as the rotor" bledes are moved toward their nel position and to tn roby maintain tbe same speed with e smaller oi water,

Upon increase of speed due to o decrease oi load, the servo-motor 3?- is caused to rolever le in a clockwise direction, and the consequent operation system to decrease the dow oi water 'to irbine l@ and to netten the tilt of the rotor blades is subllo stantially the yconverse of the abovel doscribed operations. i

Inthis specification, governor sensitivity is 'defined `as the time necessary l for the governor system to Irestore to normal the speed of the turbine upon the occurrenceof a predetermined reduction or increase in load, and may be expressed in seconds per kilowatt. Uniform sensitivity of the governor control system may be obtained by predetermining the shape of cams 31 and 46 in Fig. 1 and cams 31a and 46a in Fig. 3. In general, the cams (31 and 31a) for con-- trol ing the guide vane openingv will be steepest on the portion of these cams corresponding to no load to half load, andthe cams (46 and 46a) for controlling the tilt of the rotor blades will be stes t on the portion of these cams correspon ing to half oad to full load.

From the foregoing description,1 it will be apparent that the present invention provides a relatively sim le ,and dependable .system for adjusting tli) hydraulic turbine in accordance'with the position of the guide varies. The construction is particularlyr applicable to high speed rotary machines such as hydraulic turbines and`pumps, however, it should be understood that it is not desiredto limit the invention to -thel exact details -of construction and operation4 herein shown and described, inasmuch as various modifications within the scope of the claims may be apparent to persons skilled in the art.

It is claimed and desired to secure by `Letters Patent: f e l 1. In combination a hydraulic energy translati device aving tiltable rotor blades an movable guide vanes, a servomotor for tilting said rotor blades', a second servo-motor for movin said guide vanes, a cam for controlling t e actuation of said rotor blade tilting'servolmotor, another cam for controlling t e actuation of. said guide m vane moving servo-motor, and means res nsive to the s of said translati evice for contro ng the `actuation of sai cams. A.

2. Inl ,combination a hydraulic energy translatin device aving tiltable rotor blades an movable guide vanes, a servomotorA for tilting said rotor blades, a second servo-motor for movin said guide vanes, a cam for controlling t e actuation of said rotor blade tilting servo-motor, another caml for controlling t e actuation of said guide vane movingservo-motor, a si le speed responsive governor device, an means for causin said governor device to move both lof sai cams to obtain maximum efliciency when the s d of said translating device cha wit variation in load. 3. -Y combination a hydraulic energy 05 device aving tiltable rotor motor or ti ting said rotor blades, a second e rotor blades of a\ melma' blades and movable 'guide vanes, a servoc motor for tilting said rotor blades, a 'second servo-motor for movixg said guide vanes, a cam for vcontrolling e actuation of 'said rotor blade `tilt' servo-motor another cam for controlling t e actuation of said guide vane moving servo-motor, a thirdservomotor for actuating said cams., and means responsive to the speed of said translating device` for contro ing said third servo 75 motor. 4; A system for controlling the rotorI :blade tilt and the vguide vane opening of a f turbine com risingin combination, a servoservo-motor for actuating said guide vanes, a cam for controlling said rotor'blade tiltu ing servo-motor, a second cam forcontrollin `said guide vane actuatin servo-motor, a .t ird servo-motor for simu taneoiisly actuating both of said cams, and a speed responsive governor for controlling said third servo-motor.

5. A system for controlling the rotor blade tilt and the guide vane opening of a turbine, com rising in combination, a servomotor for ti ing 'said rotor blades, a second servo-motor for actuating said guide vanes, lgovernor mechanism responsive to the speed of said turbine,and means comprising a pair of cams actuated b said governor mechanism fory so contro 'iig both of said servo-motors that the sensitivity of said governor mechanism remains substantially constant as the load on said turbine varies.

6. In combination, a turbine having tiltable rotor blades and movable guide vanes,

means comprising `a cam controlled servomotor for tilting said rotor blades, meansl comprising a second cam controlled servo- 106 motor for moving said guide vanes, a governor mechanism responsive to the speed of said turbine, and resilient connecting means between said governor mechanism and said cams.

7. In combination, a turbine having tiltable rotor blades and movable guide vanes, a servo-motor operatively connected to said rotor blades, a second servo-motor operatively connected to said guide vanes, means comprising a pair of cams for controlling said servo-motors respectively, governor means responsive to the speed of said turbine, and connecting means between said governor means and said cams for first actuating the cam controllingsaid second servomotor and then actuating the other of said cams.

8. In combination, a turbine having tiltable rotor bladesand movable guide vanes, a servo-motor operatively connected with said Guide vanes, a second servo-motor operativelay connected with said rotor blades, means comprising a first cam for ycontrolling said first servo-motor, means comprising a 13o Y eratively connected with said rotor blades`,'

Lemme second cam for controlling said second servo-motor, a speed responsive governor means for inter-relating the movement of said cams,J and means for actuating said last' `second cam for controlling said Second second cam for controlling said second servo-motor, a speed responsive governor, and means responsive to movement of said Governor for rendering said governor uniiormly sensitive throughout the operating range of said turbine. r

1l. ln combination, a turbine having tiltable rotor blades and movable guide vanes,

a Servo-motor `operatively connected with said guide vanes, a second servo-motor operatively connected with said rotor blades, means comprising a first cam for controlling said first servo-motor, means comprising a second cam for controlling said. second servo-motor, a speed responsive governor, means dependent upon the shape of said cams for causing said servo-motors to operate at rates dependent upon the load on said turbine.

12. In combination, a turbine having tiltable rotor blades and movable guide vanes, a servo-motor operatively connected with said guide vanes, a second servo-motor opmeans comprising a first cam for controlling said lirst servo-motor, means comprising a second cam for controllingv said second. servo-motor, a speed responsive gover. nor, means dependent upon vthe shape of said vcams for causing said servo-motors to operate upon movement of said governorat such a rate that uniform governor sensitivily is maintained throughout the load Yrange o said turbine. A

13. ln combination, a turbine having tiltable rotor blades and movable guide vanes, a lservo-motor operatively connbected with said guide vanes, la second servo-motor operatively connected with said rotor blades,

means comprising a irstc'am for controlling said first servo-motor, means comprismg a second cam for controlling said second servo-motor, a speed responsive gevernor, means dependent upon the shape of said cams for causing said servo-motors to operate upon movement of said governor at such a rate that uniform governor sensitivity and maximum eciency is maintained throughout the load range of said turbine.

la. In combination, a turbine having movable guide vanos, a servo motor operatively connected with said guide venes, governor means responsive to the speed of said turbine, means actuated by said governor means for controlling operation' of said servo-notor said means ,comprising a cam havin such a contour that said servo-motor Y Wi. operate at diierent predetermined rates throughout the operating range of said governor means.

l5. ln combination, a turbine having movable guide vanos, a servo-motor operatively connected with said guide vanes, governor means responsive to the speed of said turbine, a second servo-motor 'controlled by said governor means, a cam device actuated by said second servo-motor and arranged to control said rst mentioned servo-motor, said cam device having such a `contour that said governor is edective to compensate for a given speed departure with equal facility throughout the load range of said turbine.

16. In combination, a hydraulic energy translating device having tiltable rotor blades and movable guide `venes, a rotor blade tilting servo-motor, a guide vane active y, said means also comprising a single d responsive governor device arranged to actuate both of said cams, the contour of said cams being'such that said rotor blade tilting servo-motor will move.' said rotor blades to their most eilicient position with res t to the position of said guide vanes.

testimony whereof, the signature of the inventor is ailixed hereto.

. JOSEPH J. RING.

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